Auto merge of #64868 - Centril:rollup-dheyb22, r=Centril

Rollup of 6 pull requests

Successful merges:

 - #64455 (Add Long error explanation for E0531)
 - #64546 (Bugfix/rfc 2451 rerebalance tests)
 - #64589 (Differentiate AArch64 bare-metal targets between hf and non-hf.)
 - #64763 (Add E0734 and its long explanation)
 - #64793 (Fix format macro expansions spans to be macro-generated)
 - #64799 (Fix double panic when printing query stack during an ICE)

Failed merges:

r? @ghost

Author: bors

src/librustc/error_codes.rs

@@ -2217,6 +2217,23 @@ Examples of erroneous code:
 static X: u32 = 42;
 ```
 "##,
+
+E0734: r##"
+A stability attribute has been used outside of the standard library.
+
+Erroneous code examples:
+
+```compile_fail,E0734
+#[rustc_deprecated(since = "b", reason = "text")] // invalid
+#[stable(feature = "a", since = "b")] // invalid
+#[unstable(feature = "b", issue = "0")] // invalid
+fn foo(){}
+```
+
+These attributes are meant to only be used by the standard library and are
+rejected in your own crates.
+"##,
+
 ;
 //  E0006, // merged with E0005
 //  E0101, // replaced with E0282

src/librustc/middle/stability.rs

@@ -199,8 +199,12 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
                 let name = attr.name_or_empty();
                 if [sym::unstable, sym::stable, sym::rustc_deprecated].contains(&name) {
                     attr::mark_used(attr);
-                    self.tcx.sess.span_err(attr.span, "stability attributes may not be used \
-                                                        outside of the standard library");
+                    struct_span_err!(
+                        self.tcx.sess,
+                        attr.span,
+                        E0734,
+                        "stability attributes may not be used outside of the standard library",
+                    ).emit();
                 }
             }
 

src/librustc/traits/coherence.rs

@@ -378,7 +378,15 @@ fn orphan_check_trait_ref<'tcx>(
         //      Let Ti be the first such type.
         //     - No uncovered type parameters P1..=Pn may appear in T0..Ti (excluding Ti)
         //
-        for input_ty in trait_ref.input_types() {
+        fn uncover_fundamental_ty(ty: Ty<'_>) -> Vec<Ty<'_>> {
+            if fundamental_ty(ty) {
+                ty.walk_shallow().flat_map(|ty| uncover_fundamental_ty(ty)).collect()
+            } else {
+                vec![ty]
+            }
+        }
+
+        for input_ty in trait_ref.input_types().flat_map(uncover_fundamental_ty) {
             debug!("orphan_check_trait_ref: check ty `{:?}`", input_ty);
             if ty_is_local(tcx, input_ty, in_crate) {
                 debug!("orphan_check_trait_ref: ty_is_local `{:?}`", input_ty);

src/librustc/ty/query/plumbing.rs

@@ -15,6 +15,7 @@ use errors::DiagnosticBuilder;
 use errors::Level;
 use errors::Diagnostic;
 use errors::FatalError;
+use errors::Handler;
 use rustc_data_structures::fx::{FxHashMap};
 use rustc_data_structures::sync::{Lrc, Lock};
 use rustc_data_structures::sharded::Sharded;
@@ -321,9 +322,12 @@ impl<'tcx> TyCtxt<'tcx> {
         })
     }
 
-    pub fn try_print_query_stack() {
+    pub fn try_print_query_stack(handler: &Handler) {
         eprintln!("query stack during panic:");
 
+        // Be careful reyling on global state here: this code is called from
+        // a panic hook, which means that the global `Handler` may be in a weird
+        // state if it was responsible for triggering the panic.
         tls::with_context_opt(|icx| {
             if let Some(icx) = icx {
                 let mut current_query = icx.query.clone();
@@ -336,7 +340,7 @@ impl<'tcx> TyCtxt<'tcx> {
                                  query.info.query.name(),
                                  query.info.query.describe(icx.tcx)));
                     diag.span = icx.tcx.sess.source_map().def_span(query.info.span).into();
-                    icx.tcx.sess.diagnostic().force_print_diagnostic(diag);
+                    handler.force_print_diagnostic(diag);
 
                     current_query = query.parent.clone();
                     i += 1;

src/librustc_driver/lib.rs

@@ -1231,7 +1231,7 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
     let backtrace = env::var_os("RUST_BACKTRACE").map(|x| &x != "0").unwrap_or(false);
 
     if backtrace {
-        TyCtxt::try_print_query_stack();
+        TyCtxt::try_print_query_stack(&handler);
     }
 
     #[cfg(windows)]

src/librustc_resolve/error_codes.rs

@@ -1525,6 +1525,51 @@ match r {
 ```
 "##,
 
+E0531: r##"
+An unknown tuple struct/variant has been used.
+
+Erroneous code example:
+
+```compile_fail,E0531
+let Type(x) = Type(12); // error!
+match Bar(12) {
+    Bar(x) => {} // error!
+    _ => {}
+}
+```
+
+In most cases, it's either a forgotten import or a typo. However, let's look at
+how you can have such a type:
+
+```edition2018
+struct Type(u32); // this is a tuple struct
+
+enum Foo {
+    Bar(u32), // this is a tuple variant
+}
+
+use Foo::*; // To use Foo's variant directly, we need to import them in
+            // the scope.
+```
+
+Either way, it should work fine with our previous code:
+
+```edition2018
+struct Type(u32);
+
+enum Foo {
+    Bar(u32),
+}
+use Foo::*;
+
+let Type(x) = Type(12); // ok!
+match Type(12) {
+    Type(x) => {} // ok!
+    _ => {}
+}
+```
+"##,
+
 E0532: r##"
 Pattern arm did not match expected kind.
 
@@ -1675,7 +1720,6 @@ fn const_id<T, const N: T>() -> T { // error: const parameter
 //  E0419, merged into 531
 //  E0420, merged into 532
 //  E0421, merged into 531
-    E0531, // unresolved pattern path kind `name`
 //  E0427, merged into 530
 //  E0467, removed
 //  E0470, removed

src/librustc_target/spec/aarch64_unknown_none.rs

@@ -1,4 +1,4 @@
-// Generic AArch64 target for bare-metal code
+// Generic AArch64 target for bare-metal code - Floating point enabled
 //
 // Can be used in conjunction with the `target-feature` and
 // `target-cpu` compiler flags to opt-in more hardware-specific
@@ -11,7 +11,7 @@ use super::{LldFlavor, LinkerFlavor, Target, TargetOptions, PanicStrategy};
 pub fn target() -> Result<Target, String> {
     let opts = TargetOptions {
         linker: Some("rust-lld".to_owned()),
-        features: "+strict-align".to_string(),
+        features: "+strict-align,+neon,+fp-armv8".to_string(),
         executables: true,
         relocation_model: "static".to_string(),
         disable_redzone: true,

src/librustc_target/spec/aarch64_unknown_none_softfloat.rs

@@ -0,0 +1,37 @@
+// Generic AArch64 target for bare-metal code - Floating point disabled
+//
+// Can be used in conjunction with the `target-feature` and
+// `target-cpu` compiler flags to opt-in more hardware-specific
+// features.
+//
+// For example, `-C target-cpu=cortex-a53`.
+
+use super::{LldFlavor, LinkerFlavor, Target, TargetOptions, PanicStrategy};
+
+pub fn target() -> Result<Target, String> {
+    let opts = TargetOptions {
+        linker: Some("rust-lld".to_owned()),
+        features: "+strict-align,-neon,-fp-armv8".to_string(),
+        executables: true,
+        relocation_model: "static".to_string(),
+        disable_redzone: true,
+        linker_is_gnu: true,
+        max_atomic_width: Some(128),
+        panic_strategy: PanicStrategy::Abort,
+        abi_blacklist: super::arm_base::abi_blacklist(),
+        .. Default::default()
+    };
+    Ok(Target {
+        llvm_target: "aarch64-unknown-none".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
+        target_os: "none".to_string(),
+        target_env: String::new(),
+        target_vendor: String::new(),
+        data_layout: "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".to_string(),
+        arch: "aarch64".to_string(),
+        linker_flavor: LinkerFlavor::Lld(LldFlavor::Ld),
+        options: opts,
+    })
+}

src/librustc_target/spec/mod.rs

@@ -489,6 +489,7 @@ supported_targets! {
     ("riscv64gc-unknown-none-elf", riscv64gc_unknown_none_elf),
 
     ("aarch64-unknown-none", aarch64_unknown_none),
+    ("aarch64-unknown-none-softfloat", aarch64_unknown_none_softfloat),
 
     ("x86_64-fortanix-unknown-sgx", x86_64_fortanix_unknown_sgx),
 

src/libsyntax_ext/format.rs

@@ -695,7 +695,7 @@ impl<'a, 'b> Context<'a, 'b> {
         // Now create a vector containing all the arguments
         let args = locals.into_iter().chain(counts.into_iter());
 
-        let args_array = self.ecx.expr_vec(self.fmtsp, args.collect());
+        let args_array = self.ecx.expr_vec(self.macsp, args.collect());
 
         // Constructs an AST equivalent to:
         //
@@ -724,12 +724,12 @@ impl<'a, 'b> Context<'a, 'b> {
         //
         // But the nested match expression is proved to perform not as well
         // as series of let's; the first approach does.
-        let pat = self.ecx.pat_tuple(self.fmtsp, pats);
-        let arm = self.ecx.arm(self.fmtsp, pat, args_array);
-        let head = self.ecx.expr(self.fmtsp, ast::ExprKind::Tup(heads));
-        let result = self.ecx.expr_match(self.fmtsp, head, vec![arm]);
+        let pat = self.ecx.pat_tuple(self.macsp, pats);
+        let arm = self.ecx.arm(self.macsp, pat, args_array);
+        let head = self.ecx.expr(self.macsp, ast::ExprKind::Tup(heads));
+        let result = self.ecx.expr_match(self.macsp, head, vec![arm]);
 
-        let args_slice = self.ecx.expr_addr_of(self.fmtsp, result);
+        let args_slice = self.ecx.expr_addr_of(self.macsp, result);
 
         // Now create the fmt::Arguments struct with all our locals we created.
         let (fn_name, fn_args) = if self.all_pieces_simple {

src/test/ui/coherence/auxiliary/coherence_lib.rs

@@ -5,11 +5,11 @@ pub trait Remote {
 }
 
 pub trait Remote1<T> {
-    fn foo(&self, t: T) { }
+    fn foo(&self, _t: T) { }
 }
 
 pub trait Remote2<T, U> {
-    fn foo(&self, t: T, u: U) { }
+    fn foo(&self, _t: T, _u: U) { }
 }
 
 pub struct Pair<T,U>(T,U);

src/test/ui/coherence/impl-foreign[foreign]-for-foreign.rs

@@ -0,0 +1,17 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl Remote1<u32> for f64 {
+    //~^ ERROR only traits defined in the current crate
+    // | can be implemented for arbitrary types [E0117]
+}
+
+fn main() {}

src/test/ui/coherence/impl-foreign[foreign]-for-foreign.stderr

@@ -0,0 +1,12 @@
+error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
+  --> $DIR/impl-foreign[foreign]-for-foreign.rs:12:1
+   |
+LL | impl Remote1<u32> for f64 {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   |
+   = note: the impl does not reference only types defined in this crate
+   = note: define and implement a trait or new type instead
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0117`.

src/test/ui/coherence/impl-foreign[foreign]-for-local.rs

@@ -0,0 +1,16 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+// check-pass
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl Remote1<u32> for Local {
+}
+
+fn main() {}

src/test/ui/coherence/impl[t]-foreign[foreign[t]_local]-for-foreign.rs

@@ -0,0 +1,14 @@
+#![feature(re_rebalance_coherence)]
+
+// check-pass
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+impl<T> Remote2<Rc<T>, Local> for usize { }
+
+fn main() {}

src/test/ui/coherence/impl[t]-foreign[foreign]-for-fundamental[t].rs

@@ -0,0 +1,20 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<u32> for Box<T> {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+impl<'a, T> Remote1<u32> for &'a T {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}

src/test/ui/coherence/impl[t]-foreign[foreign]-for-fundamental[t].stderr

@@ -0,0 +1,19 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[foreign]-for-fundamental[t].rs:12:1
+   |
+LL | impl<T> Remote1<u32> for Box<T> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[foreign]-for-fundamental[t].rs:16:1
+   |
+LL | impl<'a, T> Remote1<u32> for &'a T {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0210`.

src/test/ui/coherence/impl[t]-foreign[foreign]-for-t.rs

@@ -0,0 +1,16 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<u32> for T {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}

src/test/ui/coherence/impl[t]-foreign[foreign]-for-t.stderr

@@ -0,0 +1,11 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[foreign]-for-t.rs:12:1
+   |
+LL | impl<T> Remote1<u32> for T {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0210`.